The issue is that you're refusing to make a knowledge based judgement. We know Apple uses their patents offensively. We know that Microsoft, while not being particularly gruesome of late, uses their patents offensively. There is plenty of evidence for both of these claims.

We do not know that Google uses their patents offensively. At least, not that I am aware of. This doesn't necessarily mean that they won't or that they haven't. But it would be wrong to ignore past action as a predictor for future behavior.